Gas-engine.



PATENTED-MAY 15. 1906.

J. c. SGOVEL, JR.

GAS ENGINE. APPLIGATION FILED DBO. 1 .1904

rant" orrron JOHN COMES SCOVEL, JR, OF CHIOAGU, ILLINOIS.

ens-ermine,

no. sensor.

Specification of Letters Patent.

rammed ne 15, race.

Application filed Dccc mber 16, 1904. Serial No. 237,160.

Illinois, have invented a new and useful Gas.

Engine, of which-the following is a specificatron.

My inventi n relates to that class of internal-combustion engines in which the cornpressionolj the explosive mixture takes place in the saine cylinder as does the explosion; and my objects are, first, to increase the number of impulses per revolution of the shaft, while requiring but a single crank; second, to avoid stuiiing-boxes subject to the pressure and temperature of explosion third,

to secure an unusual compactness of the engine; fourth, to simplify the valve-operating and igniting mechanism, fifth, to increase the work obtainable from the fuel sixth, to diminish the noise of exhaust; seventh, to

, compress air into a reservoir while still operating as an explosive-engine eighth, to oper ate the engine with compressed air until the explosions begin and even While they are ta ring place; ninth, to turn the engine backward or reverse it by compressed The drawing accompanying this specification is a perspective dlagram of the means I employ to obtain these objects. The frame of the engine, bearin s for the shafts, and levers and guides for t e cross-head are omitted hour the drawing for the sake of clean ness.

The crank-shaft A is connected to the cross-head C by the connectingsrod B. To

this cross-head are secured four piston rods E,-F, G, and H at points equidistant fiorn the center of the cross-head pin 1, the diagonal points being opposite. Each of these pistonrods carry two istons, which travel in cylinders E E F 2 G G H H which pistons are all of the same diamete The ends of the cylinders nearest the cross-head are the lowressure ends and are provided. with stu' rig-boxes for the pist0n-rods. The ends farthest from the cross-head are the highpressure ends in which the eX losions take place and are provided with va ves E E F F &c., opcnin r inwardly, which valves may be at the si e of the cylinder, if desired.

The high-pressure ends of the cylinders are connected inside of the valves diagonally by equalizing-tubes J K L M, so that the same pressure exists at all times in the diagonal cylinders and upon the pistons E and F, G and H, and F G and H respectively. The two cylinders G and H connected togather act as one cylinder, larger, attached at I, 1n that their piston-loads are transferred equally and centrally to the cross-head pin 1.

During their forward. working stroke while the pistons G and H are being moved by the explosion the cylinders E and F are taking through the tube N and N a fresh charge preparatory to compression.

' On the suc ceedlng back stroke the products of combustion in the cylinders G and H are exhausted into the tube O by opening the valve H and into the atmosphere through the three-way cock P, which is turned so that the opening in the ln comes on top. At the same time, the va ve having been closed, the charge in the cylinders E and F is compressed and exploded at the desired moment. On the second revolution durin the forward stroke the pistbns E and F Wi 1 do the work while the valve H will be closed, and valve G will be opened, and cylinders G and 1-1 will take in a fresh charge, 'and on the backward stroke the cylinders E and F will exhaust through valve F while G and H compress ready for the next explosion. The cylinders it and F G and H Work in the same way; but the force generated in them is exerted on the cross-head during the backward strokes, so that the cross-head, and hence the crank, receives an impulse for each stroke. As these impulses'occur a" regular intervals and are equal in force the engine must turn with great regularity, and my first object is ac complished.

Since the piston-rods do not extend into the high-prcssure ends of the cylinders, it

further developed no stuffing-boxes would be needed at all and are not subject to the explosion pressure and temperature, and my second object is accomplished.

The arrangement of the cylinders'in groups side by side instead of placing them tandem on one piston-rod reduces the length occu* pied by the engine greatly, and especially so as the cylinders E and F (1 and Il occupya position alongside of the oonneoting rod, a

will be seen that if the engine were not to be space which would otherwise be Wasted.

Hence my third object is accomplished.

Each pair of admission or exhaust valves is operated by a single pivoted lever which is connected to a triangular, in e'l'lectjsingle piece, (lettered QQ Q? Q2) that is operated by IIG Ill

a crank B. This crank is caused to rotate by gears S and T with ratios of diameter of two to one and is set so that it stands at an angle of forty-five degrees upward to the fight at the moment (shown in the drawing) when the pistons are making a forward stroke. In this position of the crank the top of the valvelever H is thrown to the extreme right, opening ti, exhaust-valve in the cylinder H At the same timerthe top of the lever E forced to the left by the two rods and lever U, which connect it to lever H, open the admission-valve E angle is-connected to thevalve-levers H and E and is now in its central position, so that valves H F, E, and G are all closed.

At the center of the next or backward stroke the crank R will be downward fortyfive de ees to the right, causing the admission-va ve Gd and the exhaust-valve H to open, while the valves E (3 ,11 and F (H and F in cylinders H and F will be closed. At the same time the motion of the admission-valve levers E andE serves to make the connectionof the secondary or high-voltage circuit to the proper ignition-plug, as in thepresent position (shown in the drawing) admission-valve E is open and the insulated spring E touches the set-screw G connected to the ignition-plug G. This plug is constructed with an insulated and a grounded terminal, so as to cause a gap in the highvoltage circuit, hence a spark to ignite the charge in the cylinder. When the inletvalve G is open the spring is connected in a.

similar way to the ignition-plug E, and the same arran ement is used for the other ignition" lugs andG. Thus it is plain that theour inlet-valves, four exhaust-valves, and the four ignitionlug circuits are con trolled by a single cran B.

By switching the high voltage of the induction-coil to the proper ignition-plug but one coil is needed. This coil is lettered V, and

the secondary terminal V may be grounded on the engine at 0 while V is led to the switches W W closed by the metallic roller W and insulated from the cross-head as the cross-head nears the end of the stroke.

The primary or low-voltage circuit is controlled by a switch -X, closed at the proper moment by metallic ieces on an insulated drum rotated by the s raft A. The battery y supplies the current, and the vibrator 4) on the induction-coil serves to interrupt the primary circuit, causing a succession of sparks through the ignitionlugs. Hence one coil can be used instead 0' four, and as the eight valves and ignition-switches are operated by a single crank my fourth object is accomplished.

When working at maximum power, the pressure at release is about the same as the compression-pressure in a gas-engine, Hence there is a high releasepressure with a high The corner Q? of the t ri-- compression which might still do useful work. This, work is readily utilized by con ecting the low-pressure ends of the cvli'n rs to gether E, F, o, and H and E r (i H? b tubes 25 and 26, providing these ends wit stuffing-boxes for the piston-rods and connecting the exhaust-tubes O and O to these low-pressure ends. Thus arranged the exhaust products from the high-pressure ends of two cylinders will escape into the low-pressure ends of four cylinders and are finally exhausted by means of the piston-valve Z, moved, by means to bedescribed, in a chamber Z, connected to the low-pressure ends by tubes Z and Z The free exhaust-opening is lettered Z It will be seen that the stufiing-boxes are subject to pressure only after the products of combustion are partially expanded, and my fifth object is accomplished, and m sixth as well, since the pressure at final exhaust will be less running compound. The noise of exhaust will be less.

pressure cylinders is admitted to the exhaustconduits the exhaust-valve for the other two cylinders might open, since they are just about beginning compression To prevent this, the exhaustwalve stems ar rovided with pistons as lar e or larger than t e valveseats so arranged t at the pressure of the exhaust tends to close rather than open the valve. The pistons for the exhaust-valvcs H and F are lettered H and F The two ends of the piston-valve Z are connected by a hollow stern, and the end cham her is connected to the reservoir a by a tube 1), haning a'valve therein 0. The piston-valve opening Z and compressed by the low-pressure-ends into the reservoir a. The air thus stored up may be used to operate the engine either forward or backward by adjusting the reversing-block as desired and regulating the supply of air by the valve '0. To thisend the high pres'sure ends are su plied with relief cocks H F H, &c. l hen the engine is being started by air-pressure, as soon as the explosions begin the cooks P and P can be turned so as to make the engine work compound. The above accomplishes my eighth 4 and ninth objects.

I claim as my invention- 1. The combination of a reciprocating crosshead and two pairs of cylinders, the pistons of each pair being equal in area and con- It is also to be observed 7 that when the exhaust-pressure of the high- 'Z is operated by a reversible valve-gear (in ee sei heated to the ercss-heed at opposite points equally distant from the center from which the power is taken, and two equelizing-tuhes connecting the ends of each pair'of cylinders constantly.

2. The combination of eight equal cylin ders open at one end only and srrengedin two sets of four cylinders each, with open ends facing eseh'other and center lines coinciding of eight pistons and four piston-rods, connected to a common (Toss-heed, reeipro eating between the sets of cylinders, at points opposite and equally distant from the center of the ero'ssdieed. from which power is taken, and of equalizing-tubes connecting the elosed ends of the alternate cylinders.

13. The combination of a reciprocating cross-head, of four equal cylinders side by side, of four pistons and pistonerods attached to the eross-hesd Ll points opposite and equally distant from its center, of stuflingboxes for the pistomrods, of equalizing-wines eennecting'the farther ends ol the alternate cylinders, of equalizing-tubes connecting and a common exhsustwslve for the ends oi the cylinders nearest the cross-head, of a conduit connecting these letter equalizing-tubes with the chemhers of the exheustwzilves for the farther pairs of cylinder ends.

4. The combination of four piston-rods passing through points oFposit-e and equally distant from the center 0 a common reciprocating crossheed, each piston-rod carrying two e uel pistons at its ends, of cylinders Whose farther ends are connected in alternate pairs by eq11ali2ingtuhes and Whose nearer ends are provided .With stufiing-hoxes for Elie piston-rods, ofequalizing-tubes for the nearer. ends of the cylinders, and valves which open communication alternately with the equalizing-tuhe spans, of the ends of the cylinders nearest and on opposite sides of the crosshead and en exhaust-passage.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN COMES SCOVEL, JR.

Witnesses:

JOHN (J. ScovnL, CLARA S. Soovnn. 

